Connecting-rod structure



Sept. 27, 1927. I 1,643,720

' L. J. MOKONE CONNECTING ROD STRUCTURE Filed Feb 9. 1927 13217672507" JMc/f ONE 5 Arzs Jam-221 545 Patented Sept. 27, 1927.

I UNITE CONNECTING-BOD STRUCTURE.

LEO J. KOKONE, MINNEAPOLIS, MINNESOTA.

Application fled February 9, 1927. Serial no. mpuHEISSU maintain a firmbearing of the connecting This invention relates to an internalcombustion engine, especially to such an engine of the high speed typesuch as used in automobiles and airplanes, and the invention isparticularly directed to the wrist pm and connecting rod structure ofsuch an engine. It is well known to those skilled in the art, thattheoretically the axes of wrist pin and crank shaft bearings should beexactly perpendicular to the axis of said cylinder bore.

In spite of past efforts of engine builders, however, the axis of thewrist pin is not always exactly perpendicular to the axis of thepiston'or cylinder bore. This condition causes the connecting rod axisto be thrown out of the plane passing through the axes of the piston andcylinder and which is perpendicular to the axis of the crank shaft. Theconnecting rod thus tends to cant the piston and the piston bears morestrongly a ainst the wall of the cylinder on one si e than on the other,thus resulting in an unequal wear on the iston and in scoringand'scratching of the cy inder and piston. The pistons are oftenslightly canted so as to bear unevenly on the cylinder walls through theuneven expansion thereof, and there is often enough movement between thewalls of the piston and cylinder for the connecting rod to rock thepiston slightly when it reverses its stroke. This results in what isgenerally known as piston slap and this is the result of mal-alinementof the cylinder, piston and connecting rod. Such 3 piston and cylindertroubles are now very common in automobiles and so affect the cylindersand pistons that refitting of the pistons and reboring of the cylindersis frequently necessary. This invention is an improvement upon thatdisclosed andclaimed in a prior Patent 1,491,155, granted to applicantApril 22, 1924. With the structure disclosed in said patent, the pistonslap is eliminated. It is desirable, however, that a close fit bemaintained between the connecting rod and the wrist pin. If the hearingon the connecting rod which engages the wrist pin becomes worn so as tocause a little play, an objectionable knock or slap will occur if thepiston moves slightly laterally. It is an object of this invention,therefore,

to provide a piston, connecting rod and wrist pin structure which willpermit of lateral movement of the connecting rod without moving thepiston and will at all times rod on the wrist pin.

It is another object of the invention to provide a piston having a wristpin with a sem -spherical bearing and a connecting. rod having asemi-spherical bearing engagin the bearing on said wrist pin, a portion0 the connecting rod bearing beingyieldable.

. It is more specifically an object of this invent on to provide apassage having a wrist pin with a semi-spherical bearing thereon and aconnecting rod havinga bearing provided with a cap, a member in the capforming part of the bearing on the wrist pin which is acted upon bresilient means in the cap for holding sai member iii firm engageme'ntwith the wrist in.

has also an object 'o the invention to provide a piston, connecting rodand wrist pin structure in which the connecting rod has a yieldingbearing on the wrist pin.

These and other objects and advantages of' the invention will be fullyset forth in the following description made in connection with theaccompanying drawings, in which like reference characters refer tosimilar parts throughout the several views and in which 27- Figdl is acentral section through the assemb ed piston and connecting rod;

Fig. 2 is a view in side elevation of the upper end of the connectingrod and wrist pin, a portion being broken away and otherv port ons beingshown in vertical section;

Fig. 3 is a perspective. view partly in section of a portion of theconnecting rod and wrist pin bearing;

Fig. 4 is a view in side elevation of the wrist pin showing the bearingholding means thereon partly in section;

Fig. 5 is an end view of the wrist pin with the portions shown invertical section; 1

Fig. 6 is a view in side elevation of one form of holding means for thewrist pin bearing; and

Fig. 7 is a view of a modified form of such holding means.

Referring to the drawings, a piston such as used in an automobile engineis trated as 10 having therein piston ring grooves 10". The piston hasbosses 10 adjacent its central rtion one of which is bored to receivethe cove or bushing 11. One of the bosses 10" is bored to receive thewrist pin 12 and the other boss is bored to a larger illusdiameter toreceive a sleeve or bushing 11,

'- ing equipped with the nuts 18.

which sleeve 11 is bored to receive the other end of the wrist in 12.The wrist pm 12 has a groovel2 ormedtherem of sem1-c1rcular shape incross section, which extends.

around said wrist pin, and a 14: such as shownin Fig. 6 1s disposed in te oove 12. A semi-spherical bearing mem er 15 constructed in two halvesis placed on the wrist pin 12- and has a circumferential roove at itscentral rtion of semi-circuar shape in cross sect on, which grooveembraces the ring 14. The member 15 is made in two pieces and as shownin Figsfil and 3,

' has its outer surface of semi-spherical shape. The member 15 isembraced by the upper end of the connecting rod 16, 'said connecting rodhaving a hub 16 at 1ts lower end, bored to receive the bushing 16'' mwhich the crank shaft is journaled. The connecting rod 16 has a lowerbearing portion 16 which is formed on itsinner surface to fit the member15 and said bearing portion has oppositely projecting flanges 16.

rod, having oppositely extending flanges 16 alinin with and engaging theflan es 16, said fl anges being secured together studs 17 threaded into.the flange 16 and be- The cap member 16 has a central upstanding bossbored to form the recess 16. and having a small hole extending throughthe to thereof. A member 19 is disposed wit 'n the cap 16 formed on itsinner surface to fit the top of the member 15 and having 9. cylindricalportion 19? fittin loosely in the recess 16 at the lower end t ereof andhaving further a stem 19 extending centrally through the recess andthrough the opening in the top of the boss on cap 16". A 00' e comression spring 20 surrounds the stem 19 bearing at one end against thetop of the recess 16 and at its lower end against the shouldered to of-the portion 19.

In assembling t, e device, the wrist pin 12 will have the ring 14 lacedthereon, which rin if desired, can e slightly expanded surf moved overthe end of the wrist pin and then compressed in the groove 12'. Thebearing 15 is then placed on the wrist pin and the wrist in can beinserted through the o ening oss 10 which receives sleeve 11, t e sleeveeither being placed in said boss in the wrist pin or being subsequentlyplaced in position. The members 19 and 20 arethen placed in the cap 16and the cap placed over the member 15 and enga I with the lower portionof the connectmg rod. The nuts 18 are then placed on the studs 17 andthe same tightened. The iston and connecting rod are then assembl Inoperation the piston 10 will be recipro cated b the explosions in theengine cylinder an the connecting rod will revolve at 4 A cap member 16is provided for the connectingv y theits lower end; as the crank Shaft.Should any lateral movements occur in the piston,

they can be accommodated by the member 15 rocking inside of thesemi-spherical bearings in the upper end of the connecting rod. Themember 19 forms the upper bearing for the wrist pin or the mem er 15 andthis member will'always be held in firm engage ment with the member 15by the spring 20.

There is no 'chance,therefore, for wear to occur around the member 15 orin the connecting rod bearing which might cause a knock or slap inlateral movements of the piston. The member 19 is held in pro pfir e.position by the members 19 and 19".

connecting rod, wrist pin and piston thus function perfectly and silentlThe struc- .ture is' especially designed or very high speed engines suchas now used. on airplanes and high s eed automobiles.

If desire two rings such as shown as 21 in Fig. 7, can be placed in thegroove 12' of the wrist pin and the member 15 placed over these rings.

' From the above description it is seen that applicant has provided avery simple and e cient structure of piston, wrist in and connecting rodand one which wil accommodate all the piston movements which mightoccur. At the same time a perfect bearing will always be maintainedbetween the connecting ro and wrist pin.

In some modern pistons there is a large opening in the side so thatthepiston has very little, if any, bearing on the'cylinder below thering grooves or in the skirt portion thereof. With such istons, if thecylof the piston so that the same is not quickly made and nated. Y

Furthermore, with the yieldingly mounted portion 19 it is not necessaryto machine the bearing in the connecting rod which theslap issubstantially elimibears on the wrist pin with minute accuracy.

The semi-spherical bearing in the connecting rod on the lower portion ofthe wrist pin can be coined. The bearing surface of the member 19 alsoneed not be machined with great accuracy. The same will wear and takethe she e of the wrist pin hearing as will also the ower portion of theconnecting rod. At the same time, a firm and perfect bearing will bemaintained.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the parts, withoutdepartin from the scope of appllcants invention, w ich, generally stat-ISO ed, consists in a device capable of carrying out the objects aboveset forth, in the novel parts and combinations of parts disclosed anddefined in the appended claims.

What is claimed is 1. In combination with an engine cylinder, a pistonadapted to move therein, a wrist pin journaled therein, a semi-sphericalbearing intermediate the ends of said wrist pin, and a connecting rodhaving a semispherical bearingfitting over said bearing, saidsemi-spherical bearing on the connecting rod having a yieldingly mountedportion.

2. In combination with an engine cylinder, a piston adapted to movetherein, a wrist pin journaled therein, a semi-spherical bearingintermediate the ends of said wrist pin, and a connecting rod having arigid lower portion with a semi-spherical bearing fitting over saidsemi-spherical bearing on the wrist pin and having a resiliently mountedupper portion connected thereto fitting over the top of thesemi-spherical bearing on the wrist pin.

3. In combination with an engine cylinder, 2. piston ada ted to movetherein, a wrist pin journale therein, a semi-s herical bearingintermediate the ends of said wrist pin, a connecting rod having asemi-spherical bearing fitting over said bearing on the wrist pin and amember resiliently mounted in said connecting rod forming a part of thesemi-spherical bearing thereof.

4. In combination with an engine cylinder, a piston adapted to movetherein, a wrist pin journaled therein, a semi-spherical bearingintermediate the ends of said wrist pin, a connecting rod, a cap on saidrod, a member carried in said cap bearing against said semi-sphericalbearing on said wrist pin, and resilient means in said cap constantlyurging said member against said wrist pin bearing.

5. A connecting rod having a lower semispherical bearing fitting over aportion-of the semi-spherical bearing on said wrist pin, a cap for saidconnecting rod having a recess formed therein, a member carried in saidcap having a semi-spherical bearin fitting over the other part of saidsemi-spherical bearing on the wrist pin, said member having a portionextending throu h said recess and a spring in said recess earing uponsaid member to hold the same in en'- gagement with said semi-sphericalbearing on the wrist pin.

In testimony whereof I afiix my signature.

LEO J. MoKONE.

